3章 上机习题

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{   g();

}

private void toolStripButton1_Click(object sender, EventArgs e)
{
Form2 s = new Form2();

s.Show();
}

private void button1_Click(object sender, EventArgs e)
{
this.listView1.View = View.LargeIcon;
}

private void button2_Click(object sender, EventArgs e)
{
this.listView1.View = View.SmallIcon;
}

private void button3_Click(object sender, EventArgs e)
{
this.listView1.View = View.Details;
}
public bool g() {
if (listView1.Items.Count>0)
{
listView1.Items.Clear();

}
DBHelper s = new DBHelper();
try
{
s.OpenConnection();
string sql = @"SELECT TOP 1000 [StudentNo]
,[LoginPwd]
,[StudentName]
,[Sex]
,[GradeId]
,[Phone]
,[Address]
,[BornDate]
,[Email]
FROM [MySchool].[dbo].[Student] WHERE StudentName like '%" + this.textBox1.Text + "%' ";
SqlCommand comm = new SqlCommand(sql, s.Connection);
SqlDataReader r = comm.ExecuteReader();
while (r.Read())
{
ListViewItem i = new ListViewItem(r["StudentName"].ToString(), 0);
i.SubItems.AddRange(new string[] { r["Phone"].ToString(), r["Sex"].ToString(), r["Email"].ToString() });

this.listView1.Items.Add(i);
}
if(!r.HasRows){
MessageBox.Show("没有要查找的记录","提示",MessageBoxButtons.OK,MessageBoxIcon.Information);
}
r.Close();
}
catch (Exception e)
{
Console.WriteLine(e);

}
return true;

}

private void listView1_SelectedIndexChanged(object sender, EventArgs e)
{

}

private void chazhao_Click(object sender, EventArgs e)
{
g();
}

}

}

using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;
using System.Data;

namespace WindowsFormsApplication1
{
/// <summary>
/// 此类维护数据库连接字符串，和 Connection 对象
/// </summary>
public  class DBHelper
{
// 数据库连接字符串
private string connString = @"Data Source=.;Initial Catalog=MySchool;Integrated Security=True";

// 数据库连接 Connection 对象
private SqlConnection connection;

/// <summary>
/// Connection对象
/// </summary>
public SqlConnection Connection
{
get
{
if (connection == null)
{
connection = new SqlConnection(connString);
}
return connection;
}
}

/// <summary>
/// 打开数据库连接
/// </summary>
public void OpenConnection()
{
if (Connection.State == ConnectionState.Closed)
{
Connection.Open();
}
else if (Connection.State == ConnectionState.Broken)
{
Connection.Close();
Connection.Open();
}
}

/// <summary>
/// 关闭数据库连接
/// </summary>
public void CloseConnection()
{
if (Connection.State == ConnectionState.Open || Connection.State == ConnectionState.Broken)
{
Connection.Close();
}
}
}
}